The present invention relates to a door handle return assembly for use with a cylindrical lockset and, in particular, to a spring-biased return assembly contained in a trim ring or rose mountable on a door around the spindle means carrying the door handle.
It is known in the art to connect a door handle to a latch bolt retractor assembly mounted in an interior region in a door in such a way that a spring provided in the retractor assembly will function to return the door handle to a home or return position once the door handle is released by an operator. For example, see U.S. Pat. Nos. 4,437,695; 4,428,212; 4,424,691; 4,262,507; and 3,955,387.
Typically, an operator rotates the door handle in a selected direction away from its home position to retract the latch bolt into the door. Biasing force provided by the spring in the retractor assembly tends to oppose rotation of the door handle in the selected latch-retracting direction. Thus, upon release of the door handle by the operator, the retractor assembly spring acts to rotate the door handle in an opposite direction toward its home position as the latch bolt is also returned to its projected position.
Each door handle return spring provided in a latch retractor assembly must be carefully sized and configured to handle the loads imposed by the door handle itself. Oftentimes, a return spring designed to return a doorknob to its home position is unable to return a heavier door lever to its home position for the designed life of the spring without failing. This premature spring failure problem frequently arises whenever a doorknob is replaced by a lever handle without providing a new return spring designed to return the new lever handle.
In operation, a greater moment is applied to a retractor-engaging sleeve by the heavier, radially outwardly extending lever in comparison to the moment normally applied by an axially outwardly extending doorknob. As a result, a proportionately greater load is applied to the doorknob return spring. In many cases, such increased loads contribute to an increased failure rate of lever handle return springs.
Although, in theory, each retractor assembly could be retrofitted to include a sturdier spring each time a levered handle is installed in a cylindrical lockset designed to operate using a doorknob, this solution is not practical or desirable for a variety of reasons. It is frequently impossible to install the sturdier lever handle return spring in the space designed to receive a doorknob return spring without making major structural modifications to the retractor assembly itself. Moreover, even if the lever handle return spring could be installed in the retractor assembly, a considerable amount of field service time would have to be allocated for each retrofit activity to permit the technician to disassemble the cylindrical lockset, install the replacement return spring therein, and remount the modified lockset in the door.
The return spring included in conventional latch retractor assemblies is oftentimes not strong enough to hold a door lever in its ready-to-use position. In many cases, if the spring force generated by the return spring is increased to maintain the door lever in its ready-to-use position without drooping, the magnitude of torque which would be needed to rotate the operating key against the bias force provided by the return spring would be so great that the key would be difficult to rotate.
One object of the present invention is to provide a door handle return assembly that is easily installed on a door for use with a cylindrical lockset or the like without necessitating removal of the lockset from the door or structural modification of any component in the lockset.
Another object of the present invention is to provide a door handle return assembly that is mountable on an exterior surface of a door and configured to function for either hand of the door without further structural modification.
Still another object of the present invention is to provide a door handle return assembly that is well-suited for use with lever handles.
Yet another object of the present invention is to provide a door handle return assembly that is compact and easily installed in a trim ring or rose on an exterior portion of a door.
A further object of the present invention is to provide a door handle return assembly configured and arranged to supplement a second return assembly provided in a latch bolt retractor assembly mounted in the door.
In accordance with the present invention, a door handle assembly is provided for operating a latch bolt in a door. The assembly includes a door handle, means for supporting the door handle for rotation about an axis between a return position and operating positions, and means for retracting the latch bolt in response to rotation of the door handle by an operator away from its return position. Return means is also provided for automatically rotating the door handle from an operating position to its return position upon release of the door handle by the operator. The return means is configured to surround the door handle.
In preferred embodiments of the invention, the door handle supporting means includes a hub that is fixed against rotation relative to the door and is situated to project away from the door. The latch bolt retracting means extends through a central aperture formed in the fixed hub and is movable through that aperture relative to the hub during retraction of the latch bolt. The door handle is carried on the hub and is positioned to define an exterior space around the fixed hub between the door handle and the door. The return means is situated in said exterior space and mounted on the hub to lie in an accessible position intermediate the door handle and the exterior surface of the door.
The assembly further includes a hollow rose assembly abutting the door. The hollow rose assembly is arranged to cover and enclose the exterior space between the door handle and door to provide a home for the return means. The return means is disposed in an interior region of the hollow rose assembly to provide a compact, easily installed subassembly in the exterior space on the outside of the door which is enclosed by the hollow rose assembly.
The hollow rose assembly desirably includes a rose ring coupled to the fixed hub and a rose liner engaging the exterior surface of the door and extending radially outwardly from the rose ring. A rose cover cooperates with the door-engaging rose liner to define said interior region therebetween. The volume of the interior region between the rose liner and cover is large enough to contain the return means. The rose cover is formed to include a central aperture opening which faces away from the door. Thus, the return means is easily installed in the interior region of the hollow rose assembly by a technician by simply removing the rose cover and without substantial disassembly of the lockset.
The return means includes an elongated return sleeve extending through the central aperture in the rose cover, bearing means inside the interior region of the rose assembly for supporting the return sleeve for rotation relative to the door about the axis of rotation of the door handle, and spring means for yieldably and rotatably biasing the return sleeve to a predetermined position relative to the door. The return means further includes means for interconnecting the return sleeve and the door handle in keyed relation so that the return sleeve is rotated against the spring means in response to rotation of the door handle in either direction away from its return position by the operator. Upon release of the door handle by the operator, the spring means acts to rotate the return sleeve to its predetermined position and the door handle to its return position.
Also in preferred embodiments of the invention the retracting means includes a latch bolt retractor mounted in the door and drive sleeve means interconnecting the latch bolt retractor and the door handle for operating the latch bolt retractor in response to rotation of the door handle. Preferably, the return means is formed to include aperture means for rotatably receiving the drive sleeve means so that the return means is positioned to lie intermediate the latch bolt retractor and the door handle.
One feature of the present invention is the provision of door handle return means which interconnects the door handle supporting means and the door handle. This feature is particularly well-suited for returning heavier lever handles because its location relative to the door handle and handle support structure permits easy installation in the field. Advantageously, the feature can be used alone or in tandem with a compatible handle return assembly mounted in the door. Thus, this feature can be easily retrofitted into existing doors to assist in the handle return function as easily as it can be installed in a new door to provide the sole door handle return means.
Another advantage is that it is generally unnecessary to disassemble the latch bolt retractor assembly to permit installation of the improved door handle return means. In contrast, it would be necessary to undertake such a disassembly in order to replace an existing return spring in the latch bolt return assembly with a sturdier return spring should an existing door be upgraded to carry one of the heavier lever handles now required by many community housing codes.
Another feature of the present invention is that the return means is mountable in a location on an exterior of the door to further simplify installation. In a preferred embodiment, the return means is sufficiently compact to be mounted inside a trim or rose ring attached to the door handle support to hide the return means from view during use yet provide easy access to the mounting location during installation or repair.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.